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Nagios monitors hosts, systems, and networks, delivering alerts in real-time. Users can specify exactly which notifications they want to receive.


The program can monitor network services, including HTTP, NNTP, ICMP, POP3, and SMTP, among others.

To many, Nagios is The name in traffic monitoring. A comprehensive, all-bases-covered approach to network management. One of the most powerful free tools for cyber-security professionals and small businesses alike.

NOTE:  Nagios Log Server is the most powerful and trusted IT log analysis tool on the market. Log Server builds on proven, enterprise-level Open Source architecture to deliver a superior log monitor and analysis solution to meet any of your organization's unique needs.

Computer Software :: Information Technology and Services :: Telecommunications :: Financial Services :: Healthcare :: Retail :: Education Management 

Implementing effective server monitoring with Nagio's offers the following benefits:

  • Increased security

  • Increased awareness of network infrastructure problems

  • Increased server, services, and application availability

  • Fast detection of network outages and protocol failures

  • Fast detection of failed processes, services, cron jobs, and batch jobs

  • Audit compliance

  • Regulatory compliance


Projects uses Nagios because it is a free and open source computer software application. It is design to run on the Linux operating system and can monitor devices running Linux, Windows and Unix operating systems (OSes). 

Nagios software runs periodic checks on critical parameters of application, network and server resources. that monitors systems, networks and infrastructure, as described in the above benefits. It alerts users when things go wrong and alerts them a second time when the problem has been resolved.

Nagios monitoring work runs on a server, usually as a daemon or a service. It periodically runs plugins residing on the same server, they contact hosts or servers on your network or on the internet. One can view the status information using the web interface. You can also receive email or SMS notifications if something happens.

Nagios Core features include:

  • Monitoring of network services (SMTP, POP3, HTTP, NNTP, PING, etc.)

  • Monitoring of host resources (processor load, disk usage, etc.)

  • Simple plugin design that allows users to easily develop their own service checks.

  • Parallelized service checks.

Nagios Remote Plugin Executor (NRPE)  run checks on a system remote from the central Nagios server, allowing Nagios to query it as if the checks were run locally. In essence, Nagios talks to NRPE, asks it to run a specific check, waits for the response, and logs it along with everything else it watches.

Nagios uses the results from 
plugins to determine the current status of hosts and services on your network. Nagios will execute a plugin whenever there is a need to check the status of a service or host.

Its main database and the ndoutils module that is used alongside Nagios Core use MySQL. Prior to XI 5, PostgreSQL was used for one of the three databases it uses, and is no longer used on new installs of Nagios XI.